1. Field of the Invention
The present invention relates to sealant compositions, and more particularly, sealant compositions useful for sealing and locking threaded pipe joints.
2. Description of the Prior Art
A great variety of sealant compositions have been developed and used in numerous applications heretofore. A number of such compositions include hardenable resins which set into hard masses when catalyzed, e.g., by contact with air, by heating, by being mixed with and catalyzed by a separate hardening agent, etc.
Sealant compositions have heretofore been comprised of a hardenable liquid resin which when mixed with a hardening agent sets into a hard mass, inert solids dispersed in the resin such as powdered metal, and a thixotropy imparting agent comprised of asbestos fibers. Such compositions have functioned satisfactorily. However, with the emphasis in recent years placed on preventing health hazards brought about by the exposure to asbestos fibers when such fibers are handled and mixed, the production of such sealant compositions has been curtailed or discontinued.
The asbestos containing sealant compositions were particularly suitable for sealing and locking threaded pipe joints such as oil and gas well casing joints in that the asbestos imparted thixotropic properties to the compositions whereby they did not sag or run when placed on threads prior to joining the coated threads. Further, the asbestos functioned to keep the suspended solids in the composition from settling-out and caking at the bottom of containers during prolonged storage periods.
Thus there is a need for a sealant composition having similar or improved thixotropic properties.